转自FliteTest-电涡喷(给电动涵道加装加力燃烧室)
本帖最后由 qpswwww 于 2014-1-1 21:03 编辑大家好，我是5IMX的艾伦，这是我在模友之吧的第一帖，希望大家多多支持，最近对电涡喷很感兴趣，找到了这篇文章转载给大家，以飨模友。上次发了一次，不知道怎么回事没发成功，好像被管理员删了，这次希望能发成功，不要再被误删了，之后我会对这篇文章进行翻译。
This is my journey to discover if I could add an afterburner to an EDF model.http://assets.flitetest.com/article_images/medium/afterburner1-jpg_1363637362.jpgThis is the plane I chose. A Durafly De Havilland DH.100 Vampire. Maybe not the most obvious choice for an afterburner. But, there was an experiment to add an afterburner/reheat to a vampire back in the late 40's.http://assets.flitetest.com/article_images/medium/vamp-afterburner-jpg_1363639763.jpgUnfortunately it never go to take off as the resonance created by firing the afterburner made the booms and fuselage shake so bad that it was deemed too dangerous to fly. I love the vampire and I couldn't think of a plane more worthy of having a working afterburner.http://assets.flitetest.com/article_images/medium/afterburner2-jpg_1363637365.jpgTime to remove and inspect the EDF unit.http://assets.flitetest.com/article_images/medium/afterburner3-jpg_1363637366.jpgThe stock EDF unit out in the wild. Nothing wrong with it and it seemed quite straight forward to add the flame holder and e-flux ring to the back of it.http://assets.flitetest.com/article_images/medium/afterburner9-jpg_1363637374.jpgTo make the flame holder I used 30 gauge (0.3mm) thick galvanized steel I got from Lows.http://assets.flitetest.com/article_images/medium/afterburner10-jpg_1363637375.jpgWrapped in a circle.http://assets.flitetest.com/article_images/medium/afterburner11-jpg_1363637376.jpgFit's perfectly on the back of the motor mount.http://assets.flitetest.com/article_images/medium/afterburner4-jpg_1363637368.jpgI chose to use butane for fuel as it's easy to get, has a great burn but yet is relatively safe. Igniting it is the though bit though. I chose to try a hotwire coil first.http://assets.flitetest.com/article_images/medium/afterburner5-jpg_1363637369.jpgNicrome wire is almost impossible to solder. So in order to get a good solid connection between the nicrome wire and the the power wires I did this little trick.http://assets.flitetest.com/article_images/medium/afterburner6-jpg_1363637370.jpgA small piece of brass tubing and a big pair of pliers and you can crimp on a end that is easy to solder to.http://assets.flitetest.com/article_images/medium/afterburner7-jpg_1363637371.jpgWorks great.http://assets.flitetest.com/article_images/medium/afterburner8-jpg_1363637372.jpgCoiled the hotwire around a round tube.
http://assets.flitetest.com/article_images/medium/afterburner12-jpg_1363637378.jpgInstalled in the flame holder tube.http://assets.flitetest.com/article_images/medium/afterburner13-jpg_1363637379.jpghttp://assets.flitetest.com/article_images/medium/afterburner14-jpg_1363637381.jpgHeated up. It's controlled by a RC swtich hooked straight to the main 4S lipo.http://assets.flitetest.com/article_images/medium/afterburner15-jpg_1363637382.jpgTime to make the e-flux ring.http://assets.flitetest.com/article_images/medium/afterburner16-jpg_1363637383.jpghttp://assets.flitetest.com/article_images/medium/afterburner17-jpg_1363637385.jpgMaking some holes in the e-flux ring.http://assets.flitetest.com/article_images/medium/afterburner18-jpg_1363637387.jpg10 holes in total. 5 on the front and 5 on the back.http://assets.flitetest.com/article_images/medium/afterburner19-jpg_1363637388.jpghttp://assets.flitetest.com/article_images/medium/afterburner20-jpg_1363637389.jpgIT WORKS! Kind of... I had some real trouble getting the hotwire to work properly. When the EDF is running it cools the hotwire down so much that it's not hot enough to ignite the butane. But if the hotwire is shortened, which means it gets hotter, it can ignite the fuel but immediately burns up after ignition due to the massive temperature difference inside of the flame holder tube. I've seen others use the hotwire method on smaller EDF units with success but I came to the conclusion after a lot of experimentation that it simply doesn't work on a 70mm fan. So I tried another method...http://assets.flitetest.com/article_images/medium/afterburner24-jpg_1363637394.jpgA Stungun!http://assets.flitetest.com/article_images/medium/afterburner23-jpg_1363637393.jpgI got three of these of ebay for 25 bucks!http://assets.flitetest.com/article_images/medium/afterburner25-jpg_1363637396.jpgThe inside of the stungun.http://assets.flitetest.com/article_images/medium/afterburner26-jpg_1363637398.jpgIt works by simply stepping up the voltage from a 4s NiCd battery, which happens to be 5V. As soon as the flyback generator gets the 5V it starts outputting the ~30,000Vhttp://assets.flitetest.com/article_images/medium/afterburner27-jpg_1363637399.jpgThe only I needed. The flyback generator.http://assets.flitetest.com/article_images/medium/afterburner28-jpg_1363637400.jpgIt weighs in at 50 grams, but it's going to be worth it.http://assets.flitetest.com/article_images/medium/afterburner29-jpg_1363637402.jpgI controlled it using a simple RC switch.http://assets.flitetest.com/article_images/medium/afterburner30-jpg_1363637403.jpgAs soon as the RC channel the switch is hooked up to goes from low to high it opens up the output. In this case it just lets 5V through to the flyback generator from the stungun.http://assets.flitetest.com/article_images/medium/afterburner31-jpg_1363637405.jpgTest fitted in the plane.http://assets.flitetest.com/article_images/medium/afterburner32-jpg_1363637406.jpgSince there is going to be flames shooting out the tail pipe I though it would be a good idea to add a layer of protection in form of a aluminium foil. This particular one is copper colored on one side, which I think look pretty cool.http://assets.flitetest.com/article_images/medium/afterburner33-jpg_1363637407.jpgMarking where it need to be cut.http://assets.flitetest.com/article_images/medium/afterburner34-jpg_1363637408.jpgInstalled in the exhaust tube.http://assets.flitetest.com/article_images/medium/afterburner35-jpg_1363637410.jpgThe aluminium foil also doubles as a conductor for the stungun.http://assets.flitetest.com/article_images/medium/afterburner37-jpg_1363637414.jpgI used a 0.8mm MIG soldering wire to get the spark to jump in the low pressure zone of the flame holder.http://assets.flitetest.com/article_images/medium/afterburner36-jpg_1363637411.jpgStungun glued in place using hotglue.http://assets.flitetest.com/article_images/medium/afterburner40-jpg_1363637419.jpgThe improved flame holder. The blades help create the low pressure zone needed. Also added a metal "lid" to protect the motor from heat and sot.http://assets.flitetest.com/article_images/medium/afterburner39-jpg_1363637418.jpgFlame holder installed on the motor. The flame holder and e-flux ring are connected to the other output lead of the stungun.http://assets.flitetest.com/article_images/medium/afterburner41-jpg_1363637420.jpgComplete EDF unit installed in the fuselage. http://assets.flitetest.com/article_images/medium/afterburner42-jpg_1363637421.jpgERMAHGERD! SPERKS!http://assets.flitetest.com/article_images/medium/afterburner43-jpg_1363637422.jpgThe tail pile is connected to one output of the stungun and the e-flux ring to the other.http://assets.flitetest.com/article_images/medium/afterburner21-jpg_1363637391.jpgTo be able to dispense the butane in a easy and reliable manner, I made this little rig from some scrap wood.http://assets.flitetest.com/article_images/medium/afterburner22-jpg_1363637392.jpgThe servo simply pushes the whole butane tube forward.http://assets.flitetest.com/article_images/medium/afterburner44-jpg_1363637423.jpgTo save some weight and make space for the extra stuff I need to fit in there, I removed the landing gear.http://assets.flitetest.com/article_images/medium/afterburner45-jpg_1363637425.jpghttp://assets.flitetest.com/article_images/medium/afterburner46-jpg_1363637426.jpgButane dispenser installed. Note the angle it's at. It need to be downwards to dispense the fuel fast enough.http://assets.flitetest.com/article_images/medium/afterburner47-jpg_1363637428.jpgMain landing gear removed.http://assets.flitetest.com/article_images/medium/afterburner48-jpg_1363637432.jpg163 grams removed.http://assets.flitetest.com/article_images/medium/afterburner49-jpg_1363637434.jpgFilled the landing gear holes with foam.http://assets.flitetest.com/article_images/medium/afterburner50-jpg_1363637435.jpgSanded down.http://assets.flitetest.com/article_images/medium/afterburner92-jpg_1363637519.jpgTo regulate the the flow of butane I added a limiter in the form of a small tube. I simply squished it in the middle until I got the optimum flow of butane.http://assets.flitetest.com/article_images/medium/afterburner52-png_1363637442.jpgTest firing. The exact frame of ignition.http://assets.flitetest.com/article_images/medium/afterburner53-jpg_1363637443.jpgWohoo it works! Nice blue flame.http://assets.flitetest.com/article_images/medium/afterburner54-jpg_1363637444.jpgTime for some paint.http://assets.flitetest.com/article_images/medium/afterburner55-jpg_1363637446.jpgThe Swedish air force had 70 Vampires in service up to 1952 when it was replaced by the J 29 flying barrel. Naturally I just had to repaint this vampire in the Swedish colors to honor my comrades.http://assets.flitetest.com/article_images/medium/afterburner56-jpg_1363637447.jpghttp://assets.flitetest.com/article_images/medium/afterburner85-jpg_1363637500.jpgAdded the last trim.http://assets.flitetest.com/article_images/medium/afterburner86-jpg_1363637501.jpghttp://assets.flitetest.com/article_images/medium/afterburner57-jpg_1363637449.jpghttp://assets.flitetest.com/article_images/medium/afterburner60-jpg_1363637452.jpghttp://assets.flitetest.com/article_images/medium/afterburner58-jpg_1363637450.jpgIt works!http://assets.flitetest.com/article_images/medium/afterburner59-jpg_1363637451.jpgFire!http://assets.flitetest.com/article_images/medium/afterburner61-jpg_1363637456.jpgWrong kind of fire!http://assets.flitetest.com/article_images/medium/afterburner62-jpg_1363637458.jpgDEFENITLY THE WRONG KIND OF FIRE!http://assets.flitetest.com/article_images/medium/afterburner63-jpg_1363637459.jpgNot good...http://assets.flitetest.com/article_images/medium/afterburner64-jpg_1363637460.jpgOne of the servo wires had moved to close to the stungun wire and it arced over to the negative wire, passing through the receiver, which made it freeze up. I panicked and pulled the battery, thinking that the servo would stop pushing on the butane flask. But the servo had moved to far forward and locked on in the on position.http://assets.flitetest.com/article_images/medium/afterburner65-jpg_1363637461.jpghttp://assets.flitetest.com/article_images/medium/afterburner66-jpg_1363637463.jpghttp://assets.flitetest.com/article_images/medium/afterburner67-jpg_1363637464.jpghttp://assets.flitetest.com/article_images/medium/afterburner68-jpg_1363637474.jpghttp://assets.flitetest.com/article_images/medium/afterburner69-jpg_1363637477.jpgPlastic EDF units apparently don't like flames.http://assets.flitetest.com/article_images/medium/afterburner70-jpg_1363637479.jpghttp://assets.flitetest.com/article_images/medium/afterburner71-jpg_1363637480.jpgMelted tail pipe.http://assets.flitetest.com/article_images/medium/afterburner72-jpg_1363637482.jpgBut shame to those who give up. Here is the new EDF unit. A Change Sun 10 bladed 70mm fan.http://assets.flitetest.com/article_images/medium/afterburner73-jpg_1363637484.jpgThe Flame holder and e-flux ring survived. It just needed to be cleaned off and re soldered.http://assets.flitetest.com/article_images/medium/afterburner83-jpg_1363637497.jpghttp://assets.flitetest.com/article_images/medium/afterburner74-jpg_1363637486.jpgTime to fix the tail pipe.http://assets.flitetest.com/article_images/medium/afterburner75-jpg_1363637487.jpgI used a hotwire cutter and some blue foam to cut a new cone.http://assets.flitetest.com/article_images/medium/afterburner76-jpg_1363637488.jpgInside cut as well.http://assets.flitetest.com/article_images/medium/afterburner77-jpg_1363637490.jpgFits nicelyhttp://assets.flitetest.com/article_images/medium/afterburner78-jpg_1363637491.jpgSpackaled and sanded.http://assets.flitetest.com/article_images/medium/afterburner79-jpg_1363637492.jpgAdded two coats of water based paint, so the spray paint doesn't eat up the foam.http://assets.flitetest.com/article_images/medium/afterburner81-jpg_1363637495.jpgAs good as new.http://assets.flitetest.com/article_images/medium/afterburner82-jpg_1363637496.jpghttp://assets.flitetest.com/article_images/medium/afterburner80-jpg_1363637493.jpghttp://assets.flitetest.com/article_images/medium/afterburner84-jpg_1363637498.jpgTada! Ready for flight.http://assets.flitetest.com/article_images/medium/afterburner87-jpg_1363637502.jpgWent out to test fly it, but I ran into some trouble. The cold weather made the butane stay liquid for too long and made the combustion unstable at higher RPMs.http://assets.flitetest.com/article_images/medium/afterburner88-jpg_1363637504.jpgThis is the solution I came up with. A simple spiral of brass tubing.http://assets.flitetest.com/article_images/medium/afterburner89-jpg_1363637505.jpgThe butane now has to travel a much longer distance before getting to the e-flux ring. That gives it time to heat up and make the transition from liquid to gas form.http://assets.flitetest.com/article_images/medium/afterburner90-png_1363637512.jpgTo make it work in really cold weather I stole a nicrome wire from a RC car tire heater system and wrapped it around the coil.http://assets.flitetest.com/article_images/medium/afterburner91-jpg_1363637513.jpgThen I insulated the whole thing with foam. Plugged in to the main 4S lipo it gives about 16W of heating power, which is plenty for this application. Now time to fly!http://assets.flitetest.com/article_images/medium/afterburner93-jpg_1363637520.jpgIt's working!http://assets.flitetest.com/article_images/medium/afterburner94-jpg_1363637521.jpghttp://assets.flitetest.com/article_images/medium/afterburner95-jpg_1363637522.jpghttp://assets.flitetest.com/article_images/medium/afterburner96-jpg_1363637523.jpghttp://assets.flitetest.com/article_images/medium/afterburner97-jpg_1363637524.jpghttp://assets.flitetest.com/article_images/medium/afterburner98-jpg_1363637525.jpg
自己顶起来 顶顶更健康 自己顶起来！ huifueqweqweqweqwewqwqeqweqweqweqweqw
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